There is nothing wrong with the Oath-Keepers’ basic position opposing unconstitutional action by the authorities.
What is wrong, very wrong, is the implication that these far-fetched, paranoid scenarios are more likely under the current administration, that others in the military and law enforcement would typically go along with them, and that a positive statement of opposition is therefore necessary.

This is of course a “right-wing” organization but its premises are identical to some very long-standing and pervasive tropes of the paranoid left.